Weather helm - too much of a good thing?

[Saint]

Is there any way to figure out how much to move the center of effort based on how hard one has to pull on the tiller? I have a 13.5' open boat, Gunter rig w/ jib, Centerboard and kick up rudder. At slow to moderate speeds the weather helm is fine/tollerable. Once I am up to 5.5 - 6 mph then the helm gets quite significant. I really have to pull it over. I realize this is all completely subjective, but want to know where to start with my speculating.

Saint

[Don Maurer]

Before you mess around with trying to move the center of effort, try shifting your position towards the stern. On a small boat you can control weather helm by shifting your weight fore or aft a foot or so. You can also shift your weight forward to help you come about.

[Benchdog]

As he said move aft - hike out, etc.

If your moving at 6knots I'm guessing you are at hull speed. Probably the wind is blowing. In that case you need to reef your sail as it is over powering your rig.

[Thorne]

Benchdog -

Actually what he describes is exactly how I experienced weather helm in my dory. It was hard to steer until the wind really picked up, then it became imposible and she'd just round up in gusts. The rig was not overpowered, as the mainsail was half the sail the boat should carry.

I ended up adding a bowsprit and jib, and all is well -- just a tad of weather helm for safety but the steering struggles and rounding up are things of the past.

BEFORE -
http://www.luckhardt.com/ls-sail1.jpg

AFTER -
http://www.luckhardt.com/biglagoon1.jpg

You can try moving the centerboard to angle aft a bit -- don't know if it hangs straight down or stops angled aft, depends on the design. You can also try pulling your kickup rudder up a bit to angle aft, but these tweaks will only do so much.

Other suggestions are as above -- try shifting weight aft. Also play with the rake on your mast if you can -- rake it forward as much as possible.

Can you fly a larger jib? Try borowing one from another dinghy sailor and try it out in controlled conditions. Another option is to move your mast forward a bit, this is of course limited by the jib size/placement and your willingness to mess with the boat design.

Good luck!

[Todd Bradshaw]

And stick a couple telltales on the mainsail leech, to make sure you're not over-trimming it (which a lot of people tend to do).

[bennieboat]

when you say 'weather helm', do you mean: the force you need to hold the tiller (almost) centred? or is it the angle you hold the tiller from the centreline?

if it is about the hard pull you need, try stick the rudder way deeper (not angled aft). may be: add lenght to the tiller.

if it is about the tiller pulled way towards the luff side:

sail the boat upright (sideways: hike out, reef, whatever --- lenghtwise: sit centred, keep the transom out of the water, whatever)

experiment with the trim of your sails. Try make your mainsail pull forward instead of sideways (flatter, less twist, not so close hauled)
and yes, telltales 'at the batten ends' so you can see what is happening

when the sails work, and the tiller is still way out of the middle line, pull up the centerboard a little

yes, finally you can change the jib etc, or replace the centerboard
but think again: is the tiller more or less centred? only the force you need is exessive? change your rudder (make a balanced rudder ;-)

Ben

[Thorne]

Is your boat a one-off or experimental / home-made rig, or a developed / standardized / commercial boat with a balanced rig?

My comments were more for the former, but for the latter, much better to tweak the existing developed rig and check sail trim before adding larger sails or more spars...

;0 )